HWooldridge;
I also tried some big grape vine a few years ago. It was also strong but dirty, for me. But, all I used was off the big part of the vine. It may have been different off a smaller section.
Also, that was several years ago, and I have made a lot of changes to the way I do almost every step, so I may get much better results today.
You might run an ash test on it and if that looks good try some out. I didn't even know to do an ash test, when I tested the Grapevine.